CLEVELAND — Setting the stage on Labor Day for a critical month in their testy presidential campaign, Donald Trump softened his stance on immigration while Hillary Clinton blasted Russia for its suspected tampering in the U.S. electoral process.

In a rare news conference aboard her new campaign plane, Clinton said she is concerned about “credible reports about Russian government interference in our elections.”

“We are going to have to take those threats and attacks seriously,” Clinton told reporters traveling with her from Ohio to Illinois.

Clinton’s comments follow reports that the Russian government may have been involved in the hacking of Democratic National Committee emails just days before the party’s national convention. The emails, later revealed by WikiLeaks, showed some DNC officials favoring Clinton over her primary opponent, Bernie Sanders — who has since endorsed Clinton for president.

Meanwhile, Trump extended a rare invitation to journalists to accompany him on his private plane from Cleveland to Youngstown, Ohio. The billionaire businessman appeared to pivot away from his hard-line position on immigration, saying, “I’m all about jobs now.” Any immigrants who want full citizenship must return to their countries of origin and get in line, he told reporters — but he would not rule out a pathway to legal status for the millions living in the U.S. illegally, as he did in a long-awaited policy speech last week.

“We’re going to make that decision into the future,” Trump said.

At a Cleveland park, Clinton sharply criticized Trump’s recent trip to Mexico as “an embarrassing international incident.” Unwilling to allow Trump to modify his immigration stances, she said his address later that night in Arizona amounted to a “doubling down on his absurd plan to send a deportation force to round up 16 million people.”

The two campaigns arrived in Cleveland within hours of each other, underscoring Ohio’s quadrennial role in presidential campaigns. No Republican has won the White House without carrying the state, and the airport offered vivid imagery of that crucial role.

The airplanes of Trump and his running mate, Mike Pence, were parked on the tarmac as Clinton and her vice presidential pick, Tim Kaine, arrived in separate planes. It was a near-encounter that even forced the Trump press corps to the side of the road as Clinton’s motorcade whizzed by.

The start of full-fledged campaigning opens a pivotal month, culminating in the first presidential debate Sept. 26 at Hofstra University in Hempstead, New York. Polls show Trump trailing Clinton in a series of must-win battleground states, meaning the debates could be his best chance at reorienting the race.

Trump told reporters he does plan to take part in all three presidential debates.